[Python-ideas] namedtuple literals [Was: RE a new namedtuple]

Juancarlo Añez apalala at gmail.com
Tue Jul 25 07:19:26 EDT 2017


Steven,

(short of time here)

With **kwargs and a little more work, the function would check if the type
is already defined, and retur the ntuple with the correct type, not the
type.

Your sketch of a solution convinced me it can be done with a library
function; no additional syntax needed.

Cheers,

On Tue, Jul 25, 2017 at 5:08 AM, Stephen J. Turnbull <
turnbull.stephen.fw at u.tsukuba.ac.jp> wrote:

> C Anthony Risinger writes:
>
>  > At the end of the day, I don't see a way to have both a literal and
>  > something that is externally "named", because the only ways to pass the
>  > name I can imagine would make it look like a value within the container
>  > itself (such as using a literal string for the first item), unless even
>  > more new syntax was added.
>
> OK, so I took your "a tuple is a tuple is a tuple" incorrectly.  What
> you want (as I understand it now) is not what
>
>     def ntuple0(attr_list):
>         return namedtuple("_", attr_list)
>
> gives you, but something like what
>
>     def ntuple1(attr_list)
>         return namedtuple("ImplicitNamedtuple_" + "_".join(attr_list),
>                           attr_list)
>
> does.  Then this would truly be a "duck-typed namedtuple" as Chris
> Barker proposed in response to Steven d'Aprano elsewhere in this
> thread.  See also Nick's full, namedtuple-compatible, implementation.
> Of course we still have the horrible "list of strings naming
> attributes" argument, so you still want a literal if possible, but
> with a **key argument, a new builtin would do the trick for me.  YMMV.
>
>
> --
> Associate Professor              Division of Policy and Planning Science
> http://turnbull/sk.tsukuba.ac.jp/     Faculty of Systems and Information
> Email: turnbull at sk.tsukuba.ac.jp                   University of Tsukuba
> Tel: 029-853-5175                 Tennodai 1-1-1, Tsukuba 305-8573 JAPAN
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-- 
Juancarlo *Añez*
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